Which Fabric store supports T-SQL, KQL, and Spark reads with Spark writes?
You have a Fabric workspace. You have semi-structured data. You need to read the data by using T-SQL, KQL, and Apache Spark. The data will only be written by using Spark. What should you use to store the data?
Community Insight
The exam tests choosing a Fabric data store by its supported read and write engines; the trap is assuming a lakehouse natively serves KQL instead of requiring an Eventhouse shortcut.
Semi-structured Fabric data that must be read through T-SQL, KQL, and Apache Spark while being written only by Spark points to an eventhouse rather than a lakehouse, warehouse, or datamart. The page explains why the Eventhouse KQL database satisfies all three read paths and Spark-based ingestion.
Many candidates choose a lakehouse because it handles semi-structured data and Spark writes, but a lakehouse lacks native KQL querying; KQL access requires an eventhouse KQL database and a OneLake shortcut.
Community Discussion (89 comments)
Comments & Corrections
No comments yet — spotted an error or have a note? Share it below.
Expert Analysis
Why the Answer Is Correct
An eventhouse in Microsoft Fabric stores data in KQL databases built for semi-structured and structured data, and it exposes the exact read surfaces named in the stem: native KQL, a T-SQL endpoint, and Spark access. It also accepts Spark-based writes through the Kusto Spark connector, so the "written only by Spark" constraint does not eliminate it. That combination makes the eventhouse the only listed store that satisfies all three required read engines without adding a separate service just to translate the query language. The comment that summarized Eventhouse as "Read operations: KQL, Spark and T-SQL" captures the same capability the exam is testing.Why the Other Options Are Wrong
A lakehouse is the strongest distractor because it stores semi-structured files, accepts Spark writes, and offers T-SQL through the SQL analytics endpoint. However, KQL is not a native lakehouse query surface; reaching lakehouse data with KQL requires an eventhouse KQL database and a shortcut, which adds a second store/query layer rather than making the lakehouse itself the required store. A warehouse is optimized for structured, T-SQL-centric workloads and does not provide KQL querying or Spark-based writes as the primary write path. A datamart is a Power BI self-service semantic layer backed by T-SQL, not a semi-structured Spark/KQL store.Community Comment Notes
Several learners chose A and argued, as juamd did, that "you can query your data in a lakehouse without moving it"; that is true operationally but it describes adding an eventhouse layer, not a lakehouse-only solution. shmmini similarly saw both A and B as plausible and asked for more precision, which is exactly the ambiguity created by shortcuts. The comments supporting B focus on the decision-guide matrix, with one noting "KQL is avaialble in eventhouse only" and another listing Eventhouse read operations as KQL, Spark, and T-SQL. On an exam, the store whose native capabilities match every stated read/write requirement is the safer answer.Official Reference
Exam Strategy
Map each requirement to the native engine support listed in Fabric's data-store decision guide. If KQL is a required read path and T-SQL and Spark are also required, eliminate lakehouse, warehouse, and datamart unless the question explicitly allows shortcuts; choose eventhouse.
Frequently Asked Questions
Why isn't a lakehouse the answer if it supports Spark and T-SQL?
A lakehouse stores semi-structured Spark-written data and offers T-SQL via its SQL analytics endpoint, but KQL is not native there; you need an eventhouse or a shortcut to query it with KQL.
Can Spark write data into a Fabric eventhouse?
Yes. Eventhouse KQL databases support Spark ingestion via the Kusto Spark connector and still serve KQL and T-SQL reads.